00-24751. Airworthiness Directives; Boeing Model 767 Series Airplanes Powered by Rolls-Royce RB211 Series Engines

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 767 series airplanes powered by Rolls-Royce RB211 series engines. This action requires modification of the nacelle strut and wing structure. This action is necessary to prevent fatigue cracking in primary strut structure and consequent reduced structural integrity of the strut. This action is intended to address the identified unsafe condition.

DATES:

Effective October 17, 2000.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of October 17, 2000.

The incorporation by reference of Boeing Service Bulletin 767-57-0053, Revision 2, dated September 23, 1999, as listed in the regulations, was approved previously by the Director of the Federal Register as of July 24, 2000 (65 FR 37843, June 19, 2000).

Comments for inclusion in the Rules Docket must be received on or before December 1, 2000.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-140-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2000-NM-140-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in this AD may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

James Rehrl, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

The FAA has received reports indicating that the airplane manufacturer has accomplished a structural reassessment of the damage tolerance capabilities of the Boeing Model 767 series airplanes powered by Rolls-Royce RB211 series engines. This reassessment indicates that the actual operational loads applied to the nacelle strut and wing structure are higher than the analytical loads that were used during the initial design. Subsequent analysis and service history, which includes numerous reports of fatigue cracking on certain strut and wing structure, indicate that fatigue cracking can occur on the primary strut structure before an airplane reaches its design service objective of 20 years or 50,000 flight cycles. Analysis also indicates that such cracking, if it were to occur, would grow at a much greater rate than originally expected. Fatigue cracking in primary strut structure would result in reduced structural integrity of the strut.

Explanation of Relevant Service Information

Boeing recently developed a modification of the strut-to-wing attachment structure installed on Boeing Model 767 series airplanes powered by Rolls-Royce RB211 series engines. This modification significantly improves the load-carrying capability and durability of the strut-to-wing attachments. Such improvement also will substantially reduce the possibility of fatigue cracking and corrosion developing in the attachments.

The FAA has reviewed and approved Boeing Service Bulletin 767-54-0082, dated October 28, 1999, which describes procedures for modification of the nacelle strut and wing structure. The modification consists of the following actions:

• Detailed visual inspections for migration of the midspar, upper spar, and lower spar fitting bushings and the strut side link fitting bearings of the strut.
• Installation of new tension bolts in the aft pitch load fitting and a new side link fitting of the wing.
• Inspection and rework of the side load fittings of the wing and rework of the forward pitch load fitting of the wing.
• Replacement of many of the significant load-bearing components of the strut-to-wing attachment (e.g., midspar fuse pins, side links, side link fuse pins, diagonal brace, and diagonal brace fuse pins) with improved components.

The service bulletin contains a formula for calculating an optional compliance threshold for the specified modification. This formula is intended to be used as an alternative to the 20-year calendar threshold specified in the service bulletin.

In addition, Table 2 of the service bulletin identifies six related service bulletin modifications that must be accomplished before or at the same time as the modification in Boeing Service Bulletin 767-54-0082:

• Boeing Service Bulletin 767-29-0057: The FAA has reviewed and approved Boeing Service Bulletin 767-29-0057, dated December 16, 1993, which describes procedures for modification of the electrical wiring support of the alternating current motor pump of the main hydraulic power system. The modification involves installing new band clamps and index-straps, and on certain airplanes, new wire support brackets on the strut bulkhead.
• Boeing Service Bulletin 767-54-0059: The FAA has reviewed and approved Boeing Service Bulletin 767-54-0059, dated July 28, 1994, which describes procedures for removing the midspar fuse pins, performing repetitive detailed visual inspections for cracked or broken sealant or migration or rotation of the midspar attachment fitting bushings, and accomplishing follow-on corrective actions (including replacing the bushings), if necessary.
• Boeing Service Bulletin 767-54-0069: The FAA has reviewed and approved Boeing Service Bulletin 767-54-0069, Revision 1, dated January 29, 1998, which describes procedures for rework of the side load fitting and tension fasteners, as applicable, and replacement of midspar fuse pins with new, higher-strength midspar fuse pins. The rework involves increasing the size of the tension bolts of the inboard and outboard side load fittings. The replacement also involves installing new, higher-strength bolts and radius fillers in the side load fittings and backup support structure, and installing higher-strength fasteners common to the front spar and rib number 8 rib post.
• Boeing Service Bulletin 767-54-0083: The FAA has reviewed and approved Boeing Service Bulletin 767-54-0083, dated September 17, 1998, which describes procedures for replacement of the upper link assembly with a new, improved assembly that will increase the strength and durability of the upper link installation. That service bulletin also describes procedures for modification of the wire support brackets attached to the upper link.
• Boeing Service Bulletin 767-54-0088: The FAA has reviewed and approved Boeing Service Bulletin 767-54-0088, Revision 1, dated July 29, 1999, which describes procedures for replacement of the upper link fuse pin and aft pin with new, improved pins that will increase the strength and durability of the upper link installation.
• Boeing Service Bulletin 767-57-0053, Revision 1, dated October 31, 1996: The FAA has previously issued AD 2000-12-17, amendment 39-11795 (65 FR 37843, June 19, 2000), which requires repetitive inspections to detect fatigue cracking of the pitch load fitting lugs of the wing front spar, and rework, if necessary, in accordance with Boeing Service Bulletin 767-57-0053, Revision 2, dated September 23, 1999. “NOTE 2” of that AD states that inspections and rework accomplished prior to July 24, 2000 (the effective date of AD 2000-12-17) under Boeing Service Bulletin 767-57-0053, dated June 27, 1996, or Revision 1, dated October 31, 1996, are acceptable for compliance with that AD.

Explanation of Requirements of the Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, this AD is being issued to prevent fatigue cracking in primary strut structure and consequent reduced structural integrity of the strut. This AD requires accomplishment of the actions specified in the service bulletins described previously, except as discussed below.

Differences Between Service Bulletin and This AD

Boeing Service Bulletin 767-54-0082 recommends accomplishment of the actions in Boeing Service Bulletin 767-57-0053, Revision 1, prior to or concurrently with the actions in Boeing Service Bulletin 767-54-0082. However, as discussed above, the FAA has previously issued AD 2000-12-17 to require Boeing Service Bulletin 767-57-0053, Revision 2. Therefore, paragraph (b) of this AD requires accomplishment of Boeing Service Bulletin 767-57-0053, Revision 2, instead of Revision 1. However, as specified in “Note 2” of this AD, Revision 1 is acceptable for compliance with this requirement.

Cost Impact

None of the airplanes affected by this action are on the U.S. Register. All airplanes included in the applicability of this rule currently are operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, the FAA considers that this rule is necessary to ensure that the unsafe condition is addressed in the event that any of these subject airplanes are imported and placed on the U.S. Register in the future.

The following are costs associated with this AD that would apply if an affected airplane is imported and placed on the U.S. Register in the future:

• It would require approximately 314 work hours to accomplish the actions described in Boeing Service Bulletin 767-54-0082, at an average labor rate of $60 per work hour. The manufacturer has committed previously to its customers that it will bear the cost of replacement parts. As a result, the cost of those parts is not attributable to this AD. Based on these figures, the cost impact of this action would be $18,840 per airplane.
• It would take approximately 16 work hours per airplane to accomplish the actions described in Boeing Service Bulletin 767-29-0057, at an average labor rate of $60 per work hour. Required parts would be provided at no cost by the airplane manufacturer. Based on these figures, the cost impact of this action would be $960 per airplane.
• It would take approximately 6 work hours per airplane to accomplish the actions described in Boeing Service Bulletin 767-54-0059, at an average labor rate of $60 per work hour. Required parts would be provided at no cost by the airplane manufacturer. Based on these figures, the cost impact of this action would be $360 per airplane.
• It would take approximately 212 work hours per airplane to accomplish the actions described in Boeing Service Bulletin 767-53-0069, Revision 1, at an average labor rate of $60 per work hour. Required parts would be provided at no cost by the airplane manufacturer. Based on these figures, the cost impact of this action would be $12,720 per airplane.
• It would take approximately 1 work hour per airplane to accomplish the actions described in Boeing Service Bulletin 767-54-0083, at an average labor rate of $60 per work hour. Required parts would be provided at no cost by the airplane manufacturer. Based on these figures, the cost impact of this action would be $60 per airplane.
• It would take approximately 4 work hours per airplane to accomplish the actions described in Boeing Service Bulletin 767-54-0088, Revision 1, at an average labor rate of $60 per work hour. Required parts would be provided at no cost by the airplane manufacturer. Based on these figures, the cost impact of this action would be $240 per airplane.
• It would take approximately 5 work hours per airplane to accomplish the actions described in Boeing Service Bulletin 767-57-0053, Revision 2, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these actions would be $300 per airplane. Because the actions described in this service bulletin are already required by another AD action, this requirement adds no new costs for affected operators.

Determination of Rule's Effective Date

Since this AD action does not affect any airplane that is currently on the U.S. register, it has no adverse economic impact and imposes no additional burden on any person. Therefore, prior notice and public procedures hereon are unnecessary and the amendment may be made effective in less than 30 days after publication in the Federal Register.

Comments Invited

Although this action is in the form of a final rule and was not preceded by notice and opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the AD is being requested.
• Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2000-NM-140-AD.” The postcard will be date stamped and returned to the commenter.

Regulatory Impact

The regulations adopted herein will not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this action (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13

[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

2000-19-09 Boeing: Amendment 39-11910. Docket 2000-NM-140-AD.

Applicability: Model 767 series airplanes powered by Rolls-Royce RB211 series engines, line numbers 1 through 663 inclusive, certificated in any category.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent fatigue cracking in primary strut structure and consequent reduced structural integrity of the strut, accomplish the following:

Modifications

(a) At the later of the times specified in paragraph (a)(1) or (a)(2) of this AD, modify the nacelle strut and wing structure on both the left and right sides of the airplane, in accordance with Boeing Service Bulletin 767-54-0082, dated October 28, 1999:

(1) Prior to the accumulation of 37,500 total flight cycles, or within 20 years since the date of manufacture, whichever occurs first. Use of the optional threshold formula described in Figure 1 of the service bulletin is an acceptable alternative to the 20-year threshold, provided that the additional criteria specified in the service bulletin are met; or

(2) Within 3,000 flight cycles after the effective date of this AD.

(b) Prior to or concurrently with the accomplishment of the modification of the nacelle strut and wing structure required by paragraph (a) of this AD, as specified in paragraph 1.D., Table 2, “Prior or Concurrent Service Bulletins,” on page 3 of Boeing Service Bulletin 767-54-0082, dated October 28, 1999, accomplish the actions specified in the following service bulletins: Boeing Service Bulletin 767-29-0057, dated December 16, 1993; Boeing Service Bulletin 767-54-0059, dated July 28, 1994; Boeing Service Bulletin 767-54-0069, Revision 1, dated January 29, 1998; Boeing Service Bulletin 767-54-0083, dated September 17, 1998; Boeing Service Bulletin 767-54-0088, Revision 1, dated July 29, 1999; and Boeing Service Bulletin 767-57-0053, Revision 2, dated September 23, 1999.

Note 2:

AD 2000-12-17, amendment 39-11795, requires accomplishment of Boeing Service Bulletin 767-57-0053, Revision 2, dated September 23, 1999. However, inspections and rework accomplished in accordance with Boeing Service Bulletin 767-57-0053, dated June 27, 1996, or Revision 1, dated October 31, 1996, are acceptable for compliance with the applicable action required by paragraph (b) of this AD.

Repair

(c) If any damage to airplane structure is found during the accomplishment of any modification required by paragraph (a) or (b) of this AD, and the applicable service bulletin specifies to contact Boeing for appropriate action, then prior to further flight, repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the Manager's approval letter must specifically reference this AD.

Alternative Methods of Compliance

(d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.

Note 3:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

Special Flight Permits

(e) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Incorporation by Reference

(f) Except as provided by paragraph (c) of this AD, the actions shall be done in accordance with Boeing Service Bulletin 767-54-0082, dated October 28, 1999; Boeing Service Bulletin 767-29-0057, dated December 16, 1993; Boeing Service Bulletin 767-54-0059, dated July 28, 1994; Boeing Service Bulletin 767-54-0069, Revision 1, dated January 29, 1998; Boeing Service Bulletin 767-54-0083, dated September 17, 1998; Boeing Service Bulletin 767-54-0088, Revision 1, dated July 29, 1999; and Boeing Service Bulletin 767-57-0053, Revision 2, dated September 23, 1999; as applicable.

(1) The incorporation by reference of Boeing Service Bulletin 767-54-0082, dated October 28, 1999; Boeing Service Bulletin 767-29-0057, dated December 16, 1993; Boeing Service Bulletin 767-54-0059, dated July 28, 1994; Boeing Service Bulletin 767-54-0069, Revision 1, dated January 29, 1998; Boeing Service Bulletin 767-54-0083, dated September 17, 1998; and Boeing Service Bulletin 767-54-0088, Revision 1, dated July 29, 1999; is approved by the Director of the Federal Register, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(2) The incorporation by reference of Boeing Service Bulletin 767-57-0053, Revision 2, dated September 23, 1999, was approved previously by the Director of the Federal Register as of July 24, 2000 (65 FR 37843, June 19, 2000).

(3) Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

(g) This amendment becomes effective on October 17, 2000.

Issued in Renton, Washington, on September 21, 2000.

Donald L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.